Protein lost when fasting - Phinney vs Fung
nvmomketo
Posts: 12,019 Member
Phinney, at about 7-9 minutes in the video below, discusses how the body will use about 4oz (the equivalent of a quarter pounder) everyday after 24 hours of fasting. He says the protein catabolized peaks at about 3 days without food and then levels out but it is still about 4 oz, or a pound of muscle mass every four days, if I understand that correctly. That seemed like more than I had read in the past, and it seemed very unsustainable... I respect Phinney, hugely, but I wonder if he is off on this.
https://www.youtube.com/embed/_evJd_iZZzs?list=PLrVWtWmYRR2BYjk-oQTlAtGCjnly3J7LB
And then there is Fung who says the amount of protein catabolized goes down as the fast continues on, possibly due to increased HGH. He also says that the amount of protein lost is much much less than what Phinney states; more like just over half an ounce per day.
He also says that protein used in a fast is very easily replaceable by dietary proteins.
https://intensivedietarymanagement.com/fasting-and-muscle-mass-fasting-part-14/
"The classic studies were done by George Cahill. In a 1983 article on “Starvation” he notes that glucose requirements fall drastically during fasting as the body feeds on fatty acids and the brain feeds on ketone bodies significantly reducing the need for gluconeogenesis. Normal protein breakdown is on the order of 75 grams/day which falls to about 15 – 20 grams/day during starvation. So, suppose we go crazy and fast for 7 days and lose about 100 grams of protein. That is approximately the equivalent of 5 jumbo shrimp (my favorite oxymoron). We make up for this protein loss with ease and actually, far, far exceed our needs the next time we eat. Yes, if you fast for 7 days and then eat no other protein than 5 shrimps, you are fine."
Any ideas on what is actually correct?
I'm trying to figure out how beneficial fasting actually is (for someone who is often sedentary). I am in ketosis, or at least close to it, so there is no lag time while the body adjusts to ketones. Would being keto adapted change the situation so less protein is lost? What do you all think?
I do a very informal "fast" where I am usually done eating at 9pm, then I have BPC in the morning until after noon. I usually have around 12 hours of no food, or 15-17 hours of just BPC. I also do infrequent 1-3 day "fasts" with BPC when my BG seems to need a resetting (insulin resistance). I am not consistantly active - some weeks I do weights, walk and plymetrics whereas other weeks I do nothing - due to autoimmune arthralgias... I like fasting but do the benefits outweigh the negatives?
All thoughts and arguments would be appreciated.
https://www.youtube.com/embed/_evJd_iZZzs?list=PLrVWtWmYRR2BYjk-oQTlAtGCjnly3J7LB
And then there is Fung who says the amount of protein catabolized goes down as the fast continues on, possibly due to increased HGH. He also says that the amount of protein lost is much much less than what Phinney states; more like just over half an ounce per day.
He also says that protein used in a fast is very easily replaceable by dietary proteins.
https://intensivedietarymanagement.com/fasting-and-muscle-mass-fasting-part-14/
"The classic studies were done by George Cahill. In a 1983 article on “Starvation” he notes that glucose requirements fall drastically during fasting as the body feeds on fatty acids and the brain feeds on ketone bodies significantly reducing the need for gluconeogenesis. Normal protein breakdown is on the order of 75 grams/day which falls to about 15 – 20 grams/day during starvation. So, suppose we go crazy and fast for 7 days and lose about 100 grams of protein. That is approximately the equivalent of 5 jumbo shrimp (my favorite oxymoron). We make up for this protein loss with ease and actually, far, far exceed our needs the next time we eat. Yes, if you fast for 7 days and then eat no other protein than 5 shrimps, you are fine."
Any ideas on what is actually correct?
I'm trying to figure out how beneficial fasting actually is (for someone who is often sedentary). I am in ketosis, or at least close to it, so there is no lag time while the body adjusts to ketones. Would being keto adapted change the situation so less protein is lost? What do you all think?
I do a very informal "fast" where I am usually done eating at 9pm, then I have BPC in the morning until after noon. I usually have around 12 hours of no food, or 15-17 hours of just BPC. I also do infrequent 1-3 day "fasts" with BPC when my BG seems to need a resetting (insulin resistance). I am not consistantly active - some weeks I do weights, walk and plymetrics whereas other weeks I do nothing - due to autoimmune arthralgias... I like fasting but do the benefits outweigh the negatives?
All thoughts and arguments would be appreciated.
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So, suppose we go crazy and fast for 7 days and lose about 100 grams of protein. That is approximately the equivalent of 5 jumbo shrimp (my favorite oxymoron). We make up for this protein loss with ease and actually, far, far exceed our needs the next time we eat. Yes, if you fast for 7 days and then eat no other protein than 5 shrimps, you are fine.
This is just not going to work like this. It assumes that 100 grams of protein consumed will all be used to replace the 100 grams lost from the body tissues. It ignores the energy costs of building tissue. In general, you can lose a lot of energy in the conversion to usable body proteins. It can be 40-60%, if I recall from one of the studies on weight gain that I read.
In short, muscle losses are not easily compensated for in a single meal. It's best to avoid losing the muscle in the first place. I don't know who is closer to correct about the amount you lose (probably falls in the middle), but either way it would make me reconsider fasting for weight control.0 -
Jimmy Moore is writing a book with Fung called "Fasting Clarity." As part of his research for the book, he did a 30-day fast "coached" by Fung. He did a DEXA scan before and after. He lost 20lbs.
According to the DEXA, 10lbs of the 20lbs came from muscle. 10lb muscle loss in 30 days would be 1/3 lb per day, so even more than the quarter-pounder Phinney mentioned.
Of course, that's just an N=1. I'm a huge fan of Cahill's work, but his N was small too.
I assume Phinney has read Cahill. I don't know where the quarter-pounder comes from, though. My recollection matches what you've quoted about Cahill's study.
Glucose needs are about 40g/d. Protein converts to glucose at about 7:4. About half of glucose comes from glycerol via GNG, so that leaves 20g that must come from protein, or about 35g of protein per day.
Much less than the 100g implied by Phinney, but Phinney's estimate is closer to what Jimmy Moore measured.0 -
All to technical for me.1
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Seems like a safe bet that accurate estimates would be somewhere in the middle.0
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So, suppose we go crazy and fast for 7 days and lose about 100 grams of protein. That is approximately the equivalent of 5 jumbo shrimp (my favorite oxymoron). We make up for this protein loss with ease and actually, far, far exceed our needs the next time we eat. Yes, if you fast for 7 days and then eat no other protein than 5 shrimps, you are fine.
This is just not going to work like this. It assumes that 100 grams of protein consumed will all be used to replace the 100 grams lost from the body tissues. It ignores the energy costs of building tissue. In general, you can lose a lot of energy in the conversion to usable body proteins. It can be 40-60%, if I recall from one of the studies on weight gain that I read.
In short, muscle losses are not easily compensated for in a single meal. It's best to avoid losing the muscle in the first place. I don't know who is closer to correct about the amount you lose (probably falls in the middle), but either way it would make me reconsider fasting for weight control.
Fung's ideas do seem overly simplified to me too. It can't be that simple.
I have read that there is no real muscle loss in the first 12-16 or so hours. I have also heard that gluconeogensis is responsible for all glucose after a little over a day fasted. I guess I should assume that those of us in ketosis are already there? That's when muscle mass is loss... I know I've read elsewhere that ketosis is muscle sparing, so I would think fasting would be similar.
LOL I'm confused.Jimmy Moore is writing a book with Fung called "Fasting Clarity." As part of his research for the book, he did a 30-day fast "coached" by Fung. He did a DEXA scan before and after. He lost 20lbs.
According to the DEXA, 10lbs of the 20lbs came from muscle. 10lb muscle loss in 30 days would be 1/3 lb per day, so even more than the quarter-pounder Phinney mentioned.
Of course, that's just an N=1. I'm a huge fan of Cahill's work, but his N was small too.
I assume Phinney has read Cahill. I don't know where the quarter-pounder comes from, though. My recollection matches what you've quoted about Cahill's study.
Glucose needs are about 40g/d. Protein converts to glucose at about 7:4. About half of glucose comes from glycerol via GNG, so that leaves 20g that must come from protein, or about 35g of protein per day.
Much less than the 100g implied by Phinney, but Phinney's estimate is closer to what Jimmy Moore measured.
Do you know how much of Moore's loss was water?
I came across this link comparing the protein, fat and water weight lost between a starvation diet, and an 800kcal ketogenic and mixed diet, based on the article, Metabolic Responses of Obese Subjects to Starvation and Low-Calorie Ketogenic and Nonketogenic Diets.
It lists the Diet type and then Total weight loss = Fat weight loss + Protein weight loss + Water weight loss
Mixed diet 277.9 g/day = 166.7 g/day + 9.5 g/day + 101.7 g/day
Ketogenic diet 446.6 g/day = 163.4 g/day + 17.9 g/day + 265.3 g/day
Fasting 750.7 g/day = 243.1 g/day + 50.4 g/day + 457.2 g/day
The water weight lost is significant. I have my fingers crossed that some of Moore's losses were actually water. 10lbs of muscle loss in a month seems just brutal.
How could that be a book in favor of fasting if he lost that much muscle? Almost 2.5 lbs per week? Yikes.
Especially disturbing is that the average woman can only gain 0.5-1 lb of muscle per month (men gain 1-2lbs). I would take a year to rebuild a 10lb muscle loss.
I wish I had money and could experiment with DEXA or double labled water before I go too far down the wong road. As it is, the only way I'll know I've done my body some harm is for it to get bad enough for me to actually notice.
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LOL I know. My brain is getting a workout.SuesNewImage wrote: »All to technical for me.
Sunny_Bunny_ wrote: »Seems like a safe bet that accurate estimates would be somewhere in the middle.
The middle, with Moore's results thrown in would be somewhere in between 15g and 150g. 15g seems overly conservative now.... A quarter pounder of lean mass lost per day is just a disturbing visual.
... I need to do some more reading on muscle sparing diets and fasting now. LOL1 -
I think the 20lbs mentioned by Moore was all tissue, no water. DEXA only looks at tissue (via low-powered x-rays).
ketosis is muscle sparing
Context is important. Ketosis is muscle sparing compared to the alternative during starvation. If the brain continued to need 130g/d of glucose during starvation, and glycerol provided 20g, then 110g/d glucose would have to come from muscles. That would mean muscle losses of 200g/d. So ketosis spares about 165g/d of muscle losses. That's hugely sparing.
Definitely look into the protein-sparing modified fasts. Those are specifically formulated to minimize muscle losses.
What you'll find is that the protein intake is relatively high. In fact, you'll find it's identical to a "well-formulated ketogenic diet."
Why? Because keto = PSMF + fat. That's all keto is.1 -
Definitely look into the protein-sparing modified fasts. Those are specifically formulated to minimize muscle losses.
What you'll find is that the protein intake is relatively high. In fact, you'll find it's identical to a "well-formulated ketogenic diet."
Why? Because keto = PSMF + fat. That's all keto is.
Makes perfect sense - thanks for the simple explanation!0 -
I know jimmy has made comments about DEXA not even being as accurate as we would like to think. It apparently cannot differentiate between muscle and other tissue (or something like that) so that 10 pounds according to what he's said since then isn't actually thought to be all muscle.
I believe he mentioned doing multiple scans close enough together that you wouldn't expect to get a different measurement, but getting different results. I don't recall the details, but overall he was talking about the Dexa not being as accurate as people tend to think.0 -
Just out of curiosity, anyone have lab values done say fasted 16+ hours? In particular, Serum Creatinine, Blood Urea Nitrogen (BUN), Total Protein, Albumin, Globulin, Urinalysis (proteinuria, presence of casts, sp. gravity).
Short term markers tend to show myself being in a catabolic state/amino acid breakdown, whereas long term markers show nothing unusual. Of course, I fast 20-24 hours/day.
Wabmester is on point, keto "starvation" is not = to kcal starvation (pre-albumin/transthyretin being the marker). 2nd, I still don't understand why people would want to fast for > 72 hours2 -
Here's a nice graph from Owen (who worked with Cahill) on nitrogen losses in urine.
It doesn't cover hour-by-hour, but it's still instructive. This patient lost 100g protein after 1 day of fasting, and that leveled off to 25g/d after 4 weeks.
100g is close to a quarter-pounder. 0 -
Nice chart wabmester, I like the compensation aspect of the dramatic increase proportion in ammonium loss; water soluble form of ammonia...too much and you've got some hepatic encephalopathy.0
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It the IF thread I posted to PDF links of books over 100 years old on fasting for medical reasons in that era. The longest total fast record was 50 days. They was showed a gross daily loss of about 3/4 to one pound. Accord to one book a lot of health issues resolve including arthritis pain. If I had done a total fast for 30 days I expect I would have achieved the 30 day pain drop like I did in nutritional ketosis and would have called the total fast a 'cure'.
Does anyone have any literature that indicates total fasting offers any advantages that can not be achieved with nutritional ketosis.
V_Keto_V I am with you on the 72 hour max which I have never tried.0 -
I like the compensation aspect of the dramatic increase proportion in ammonium loss; water soluble form of ammonia...
Those ammonium cations are also thought to be sodium-sparing. My understanding is that they couple with excreted ketone anions. That's why people lose so much water and sodium in the first week of going low-carb.
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I think the 20lbs mentioned by Moore was all tissue, no water. DEXA only looks at tissue (via low-powered x-rays).
ketosis is muscle sparing
Context is important. Ketosis is muscle sparing compared to the alternative during starvation. If the brain continued to need 130g/d of glucose during starvation, and glycerol provided 20g, then 110g/d glucose would have to come from muscles. That would mean muscle losses of 200g/d. So ketosis spares about 165g/d of muscle losses. That's hugely sparing.
Definitely look into the protein-sparing modified fasts. Those are specifically formulated to minimize muscle losses.
What you'll find is that the protein intake is relatively high. In fact, you'll find it's identical to a "well-formulated ketogenic diet."
Why? Because keto = PSMF + fat. That's all keto is.
That does make sense. Thank you.
I am thinking that I need to cut back on my fat intake anyways. I am eating a lot lately, at maintenance levels, but I'd still like to lose around 10 lbs. My body isn't going to use my fat if I am eating so much of it.
This makes me wonder why the idea of extending a a fast with fats, like in BPC, is so popular. I tend to do it but I began because I liked the taste. I used to add a protein powder to it because I also liked the taste, and I often skipped breakfast as a preference and found meeting my protein minimums difficult.
The few times I have fasted for over 24 hours I had a small amount of fats in my coffee too. Makes me wonder if I shouldn't add a bit of PP too. (I like PP as it doesn't seem to make me want to eat like other food can.)Here's a nice graph from Owen (who worked with Cahill) on nitrogen losses in urine.
It doesn't cover hour-by-hour, but it's still instructive. This patient lost 100g protein after 1 day of fasting, and that leveled off to 25g/d after 4 weeks.
100g is close to a quarter-pounder.
I wonder if those keto adapted would have different numbers because they may use their triglycerides more effectively?1 -
Just out of curiosity, anyone have lab values done say fasted 16+ hours? In particular, Serum Creatinine, Blood Urea Nitrogen (BUN), Total Protein, Albumin, Globulin, Urinalysis (proteinuria, presence of casts, sp. gravity).
Short term markers tend to show myself being in a catabolic state/amino acid breakdown, whereas long term markers show nothing unusual. Of course, I fast 20-24 hours/day.
Wabmester is on point, keto "starvation" is not = to kcal starvation (pre-albumin/transthyretin being the marker). 2nd, I still don't understand why people would want to fast for > 72 hours
Out of curiosity, what is short term and long term for you?
I wouldn't want to go more than 2-3 days fasting unless there was therapeutic health reasons that required it. I like food. 0 -
GaleHawkins wrote: »It the IF thread I posted to PDF links of books over 100 years old on fasting for medical reasons in that era. The longest total fast record was 50 days. They was showed a gross daily loss of about 3/4 to one pound. Accord to one book a lot of health issues resolve including arthritis pain. If I had done a total fast for 30 days I expect I would have achieved the 30 day pain drop like I did in nutritional ketosis and would have called the total fast a 'cure'.
Does anyone have any literature that indicates total fasting offers any advantages that can not be achieved with nutritional ketosis.
V_Keto_V I am with you on the 72 hour max which I have never tried.
I think Fung talks about the longest fast being just over a year; 387 days keeps popping into my head but I could be wrong.
I'm curious about ketosis vs fasting advantages and disadvantages too. I'll have to look more into this when I get a bit more time.0 -
I wonder if those keto adapted would have different numbers because they may use their triglycerides more effectively?
I would love to see a study that asked that question!
It looks like the body reaches some sort of steady-state after 4 weeks. What perturbs that state?
"Fat adaptation" is probably part of it, but I've never seen a good description of what that adaptation is.
Personally, I think we're mostly seeing the kidneys adapt. In Moore's case, he didn't fast for 30 days straight. He broke it up with meals (once a week?). Maybe that reset the kidney adaptations, and he went back to losing the maximum amount of protein again.
There have been some experiments that give us some insight. For example, carb intake during a fast causes an increase in uric acid excretion. Fat intake (in the form of cream) seemed to cause no change in urine nitrogen.2 -
That makes sense too. Always enjoy hearing your thoughts on things. 1
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